Electrical connector



Nov. 14, 1939. c, KQEHLR ELECTRICAL CONNECTOR Filed Marron 9, 195s y wrm 7 7 7 J 2 w y uIE Patented Nov. 14, 1939 UNITED STATES PATENT OFFICE Charles H. Koehler,` Oak Park, Ill.

Application March 9, 1936, Serial No. 67,849

8 Claims.

This invention relates to electrical connectors, and more particularly is directed to such connectors for establishing connection between two fixed terminal members by means of an intermediate connecting lmember having relative movement witlirespect to the terminal members.

The present invention is a continuation in part of my copending application, Serial No. 30,283, filed July 8, 1935,nowPatent No. 2,123,631, patented July 12,1938, and is concerned with the provision oi a switching member capable of maintaining substantially uniform equalized contact pressure between the terminal members and the connector irrespective of limited misalignment between the terminal members.

One of the primary objects of the present invention is the provision of means for readily connecting and disconnecting equipment such as switches, circuit breakers, connectors and the like, in their respective circuits, with compensation for axial and other misalignment of the parts, while assuring maintenance of equalized contact pressure of ample unvarying contact area in all positions of such misalignment.

In its preferred embodiment, the present invention contemplates a means for connecting two xed contact terminals with a floating self-aligning connector, mechancally or manually moved into and out of operative position.

One of the objects of the present invention is to provide a means for connecting the studs of a circuit breaker or the like with the associated stationary contacts, by means of a floating-selfaligning connector which maintains, in all allowable positions of misalignment, an equalized contact pressure of unvarying contact area.

Another object of the present invention is to provide a substantially resilient contact engagement between the connector member and the terminal member by forming one of the members of a plurality of contact shoes which are pressed into equalized engagement with the other member regardless of the angular misalignment therebetween, and which provide a substantially uniform contact area in all positions of engagement.V

Still another object of the present invention is the elimination of spring means from any part of the electrical circuit through the terminals, whereby the life of the springs is materially increased.

In the provision of a disconnecting .device or connector for connecting and disconnecting two spaced terminals, special requirements usually demand a compact but sturdy construction. The

' present invention iinds particular application for (C1. 20G-46B) such use and produces a high grade eii'icient contact device. Also, because of its self-aligning characteristics, the present invention is capable of being employed in connection with the terminals of circuit breakers, if desired, since the 5 sockets or terminals of such breakers must be self-adjusting and capable of maintaining equalized contact pressure upon the male contact plugs with which the breaker terminals are engaged when the breaker is connected in switch- 10 closed position. It is to be understood, however, that the invention is not to be limited to these specic uses, since the broad features thereof are applicable in various other fields.

Other objects and advantages of the present 1i invention will appear more fully from the following detailed description which, taken in conjunction with the accompanying drawing, will disclose to those skilled in the art the particular construction and operation of a preferred form of 20 the present invention. i

In the drawing:

Figure 1 is a vertical sectional view through one form of switch connection embodying the principles of the present invention;

Figure 2 is a corresponding vertical sectional view of a second form of the invention;

Figure 3 is a sectional view taken substantially on line 3 3 of Figure 2;

Figure 4 is a sectional view taken substantial- 30 ly on line 4-4 of Figure 2;

Figure 5 is a sectional view corresponding to Figure 3, showing a modied form oi spider construction; and

Figure 6 is a sectional view taken substantially 35 on line 6-6 of Figure 5.

Referring now in detail to the structure shown in Figure l, I have disclosed a form of connection in which only two areas of Contact are required to effect electrical connection between a pair of spaced contacts.

In this construction, I provide a iixed contact member I0, having a normally extending arm I2 supported on a suitable supporting bracket I3. The contact member IU is provided with a ball tip end I4, and is also provided with a longitudinally extending central passageway I5 receiving the internally threaded sleeve I6 which is mounted therein and which is adapted to receive the threaded shaft Il projecting therethrough.` The 50 sleeve I6 has an extending portion projecting below the Contact I0 and carrying the bevel gear member I8 keyed thereto. The gear I8 is driven by a second gear member I9 supported on adriving shaft 20.

The threaded shaft I1 is adapted to reciprocate within the passageway I5 upon rotation of the gear I8, the shaft I1 having a suitable stop member 22 limiting its downward movement within the passageway I5. 'Ihe stop 22 slides in a suitable keyway 23 formed in the passageway I5 to prevent rotation of the shaft I1 and to provide for only longitudinal movement thereof. The upper end of shaft I1 has a socket 2| receiving the ball end of a pin 24 mounted for universal movement about the upper end of the shaft |1.

At its upper end, the pin 24 is provided with the spider member 25 having radially extending arms 26 passing through suitable openings formed in a plurality of contact shoe members or bars 21, the outer lateral surface of the contact bars 21 being provided with tapered recesses 28 receiving the helically coiled spring members 29 carried by the arms 26 and biased at their outer ends against a stop plate 39 secured to the outer ends of the arms. This provides for resilient movement of the contact bars 21 inwardly and outwardly with respect to the spider 25, and also ,I provides for resilient and uniform equalized contact pressure of the bars against the ball tip end 3| of a contact member 32 fixed at a predetermined distance from the contact I0. l

The lower ends of the contact bars 21 are also ,K provided with tapered recesses 33 formed in the Iouter lateral surfaces thereof, which recesses are adapted to receive helically coiled springs 34 normally biasing the lower ends of the contact bars into contact engagement with the ball tip I4 of the contact I0. The springs are maintained in proper biasing position by an encircling housing member 35 having suitable inset portions 36 forming spring seats for the springs 34. In this manner the lower ends of the Contact bars 21 are biased inwardly into uniform equalized "contact pressure of unvarying area Awith the lateral surface of the ball tip I4. Preferably, the inner contacting surfaces of the contact bars 21 and the ball tips I4 and 3| of the contacts I0 and 32 are silver plated in order to reduce the resistance to passage of current therethrough.

` 'the shaft I1 downwardly within the passage I5,

In the operation of the structure shown in Figure 1, in the position shown in this figure the contact bars 21 have been moved upwardly to provide for contacting engagement between the contacts I0 and 32. When it is desired to disconnect the electrical connection between these contacts, the shaft 29 is rotated by any suitable driving means to effect corresponding rotation of the sleeve I6. This results ink threading of and results in corresponding movement of the contact bars 21 due to their engagement by the arms 26 of the spider 25 secured on the sleeve member, away from the ball tip 3|, disconnecting the contact IU therefrom. At the same time,

the lower ends of the contact bars are moved downwardly past the ball tip I4 of the contact I9 until the contact bars 21 assume a position with the spider 25 disposed immediately above the ball contact tip I4 of the contact II), with the lower ends of the contact bars 21 being disposed about the lower cylindrical portion of the contact I0.

This provides a suitable clearance between the contacts IU and 32, and at the same time produces wiping engagement of the inner surfaces of the contact bars 21 across the ball contact tip I4, and also across the ball contact tip 3| when the bars are moved upwardly into contact engaging position. This is advantageous in providing clean and positive contact between the contact tips and the contact bars, thus reducing the resistance through the connection. At the same time, the spring mounting of the contact bars 21 at their upper and lower ends assures that equalized contact pressure of unvarying uniform area will be provided between the contact tips I4 and 3| and the portion of the bars in engagement therewith.

Obviously, the reciprocatory movement of the contact bars 21 might be secured by other means than the threaded shaft fitting into the sleeve I6, and I do not intend to limit my invention to this specific form of actuating mechanism, since a suitable plunger member might be employed for producing the same mode of operation. Further, even if a slight misalignment of the contacts 32 and I0 is present, the resilient mounting of the contact bars 21 upon the sleeve or pin 24 insures that such misalignment will be accommodated, and that equalized contact pressure will be produced regardless of such misalignment.

Considering now in detail the embodiment of the invention shown in Figures 2 to 4, inclusive, a contact stud 49 is provided with an extending threaded portion 42 receiving a support member 43 threaded thereover and having a laterally extending portion 44 which receives a hollow metallic tube 45 threaded into a recess formed in the portion 44 of the member 43.

Within the lower end of the tube 45 there is provided a bushing 46 which has an annular shoulder 41 seating on the bottom of the recess into which the tube 45 extends. The bushing 46 also has an extending cylindrical portion 48 which extends into a suitable recess formed in the member 44, the bushing serving as a guide for the lower end 49 of a threaded shaft 5D, which shaft at its lower end is provided with a helical gear 52 having bearing support within a suitable supporting bracket member 53. Suitable thrust washers 54 are provided at opposite ends of the gear 52, and the gear is adapted to be rotated by a second helical gear 55 carried within suitable bushings 56 extending into opposite ends of a cylindrical recess formed in the member 53. Suitable graphite or other bearing members 51 are interposed between the ends of the gear 55 and the bushing 56, the bushing 56 being bolted into position by means of the stud bolts 58 threading into the lateral walls of the bracket 53.

The bracket 53 is also provided with oppositely extending flanged shoulders 59, which shoulders are adapted to receive suitable stud members 69 securing the bracket 53 to the portion 44 of the member 43. It will be noted that the bracket 53 may be rotated through a limited arc with respect to the member 44 in order to provide for variation in alinement between the member 44 and the shaft 62 which carries the gear 55.

The shaft 62 extends outwardly of the bushing 56 and is provided with squared end portions 6-3, one of the end portions 63 receiving a crank member 64 whereby the shaft 62 may be rotated in opposite directions to produce corresponding rotation of the threaded shaft 50.

The upper end of the tubular member 45 is provided with a relatively spherical external bead 65, which bead is adapted to form a suitable contact surface engaged by a plurality of contact shoes 66 having the arcuate inner surfaces thereof engaging about the bead 65 at the lower end thereof. The contact shoes 66 are also provided with concave recesses 61 accommodating the universal movement of the assembly as it moves toward contact engaging position. A'plurality of spring members of cupped cross section, indicated at 58, are adapted to engage in suitably notched portions of the external surface of the members 65, being held in position by means of a polygonal band 5S surrounding the shoes and connected with the spring 68 by means of the adjustable threadedv pin members lll which have suitable seating engagement in the arched portions of the spring 63. This serves to urge the shoes 56 resiliently into engagement with the upper end of the tubular member 45 and to maintain equalized pressure between each of the shoes and the contact surface of the member 45.

, The threaded shaft 5@ is provided with a spherical traveling nut l2 adapted to move upwardly and downwardly on the shaft 50 by means of the pin 'i3 guided in the keyway 14 formed in the internal surface of the member 45, whereby the nut l2 is prevented from rotation and threads upwardly and downwardly upon the shaft 56 as the shaft is rotated.

A suitable supporting sleeve 'i5 is provided at its lower end with a socket portion l5 welded or otherwise suitably secured thereto which engages about the spherical surface of the traveling nut 'if to provide for substantially universal movement of the sleeve "l5 about the member l2. The beaded contact surface 65 has a center of curvature disposed at a point common to the center of the ball nut l2 and the center of the internal surface of the socket portion 15. The socket portion i6 of the member 'l5 is suitably milled out as shown at 'il about the pin i3 to provide for this universal movement of the sleeve 'l5 about the traveling nut.

The upper end of the sleeve l5 is provided with an annular disc-like member or spider Bil having a plurality of radially extending slots milled into the outer surface thereof, which slots are adapted to receive radially extending blade or cam members 82, the members 82 extending radially outwardly of the spider 8|) and being suitably welded or otherwise secured in the milled out slots formed in the outer surface of the spider 89. The upper ends of the shoe members 68 are slotted, as indicated at t3, from the end longitudinally to a point below the kextending arm i2 of the spider 8f4. lSuitable leaf spring members 84 are mounted in vertical extending positions on the external surface of the shoes 65 by means of bolts 85 threading into theshoes 6B.

Retaining means 35 are carried vby each of the arms 892 at the end thereof, whereby the shoes 56 are supported upon the arms 82 by means of the bearing yof the spring members on the upper edges of the arm d2. This provides for resilient mounting of the shoe members upon the spider 80, whereby the shoe members may move radially inwardly and outwardly under `the pressure of springs 84 to be expanded or contracted, as desircd.

A hollow contactu sleeve 90, or any other desired type of contact, is mounted in fixed position above the tube d5, and has an externally enclosing insulating member 92 carried thereabout and maintained in predetermined position with respect to the contact sleeve Sil by means of the lock nut t3 bearing against the lower end of the insulator 92 threaded onto the contact sleeve. The lower end of the sleeve Sil lis provided with a spherically curved portion 9| which is of sub-k stantially the same radius as the curved bead 65 be, engaged by the shoes 66 which have a cylindrical surface of a radius substantially equal to the radius of the curved surface 9|. y

In the operation of the construction shown in Figures 2 to 4, inclusive,` rotation of the crank 64 serves to rotate the shaft 50, causing the nut l2 to travel longitudinally of this shaft. This results in downward movement of the member l5 from the position shownin Figure 2, which results in drawing of the upper ends 83 of the shoes 65 downwardly out of engagement with the contact end of the sleeve 90, thereby breaking contact between the contact surface 9| and the contact 40. This downward movement is accommodated by means of the recess portions v6l of the shoes 66 which fit around the beaded portion 55 of the tubular member 45. The traveling nut 'i2 can move downwardly upon the shaft 50 until the spider 80 rests upon the upper surface of the tubular member 45. Inasmuch as the normal external diameter of the tubular member 45 is substantially less than the beaded portion 65 thereof, or the externaldiameter of the contact sleeve Si', the shoes will be expandad against the pressure of springs 68 and 83 when in the position shown in Figure 2. Consequently, upon downward movement, the shoes will contract, but cannot contract inwardly beyond the external diameter of the member 80, or the external diameter of the member 45. When the shoes have reached their lowermost position, the upper ends thereof are contracted to a slight extent by reason of the pressure of springs 84, so that upon upward movement into switch closing position, the shoes will be spread radially as they come into engagement with the contact surfaces 9| of the sleeve Si), due to the upwardly and outwardly haring end portions 83 thereof, so that any slight misalignment of the contact 9i) and the tubular member 45 will be accommodated by theswinging movement of the sleeve l5 about traveling nut l2, the sleeve having substantially universal movement about this nut so that as the contact shoes are guided into engagement, the sleevevmay rotate about the nut in any desired manner to accommodate any misalignment which may be present. This brings the shoes in uniform contact engagement therewith, Also, by reason of the particular spring mounting disclosed, equalized contact pressure of each of the shoes against the stationary contact is provided, and the wiping action of the shoes across the contact surfaces serves to maintain the surfaces clean and brightf In Figure 5 I have shown a modified form of spider for supporting the upper end of the contact bars. In this embodiment of the invention, the sleeve l5 is provided with a spider |00, which is `formed with a plurality of circumferentially spaced openings |62 adapted to receive the contact shoes H53 corresponding to the contact shoes SES of Figure 2. The outer peripheral surface of the spider Hill is formed of a polygonal shape corresponding to the number of shoes forming the connector. The shoes are supported against movementwith respect to the spider |50 by engagement of a spring member |0115 with a notched portion W5 on the outer surface of each of the shoes m3, as shown in more detail in Figure 6. The springs are held -in position by rivet members l0?, secured to the outer surface of the spider |55 and extending into the openings |02. Suitable web portions l are provided in the spider for separating the various openings |02 through which the respective shoes |03 extend. By rea,-

pressure engagement with the surface SI son of this arrangement, the shoes |33 are normally pressed inwardly to form a cylindrical surface which is slightly smaller in diameter than the contact surface 9i of the contact 9U. Thus, when the shoes are moved upwardly by rotation of the crank 64, the upper ends thereof are spread apart upon engaging the contact surface 9|, and the shoes are held in equalized contact by reason of the springs IM. The cylindrical surface defined by the inner contact surfaces of the shoes and the spherical surface Si of the contact SU insure that an unvarying contact area -will be provided regardless of the misaligriment of the contacts, and also that equalized pressure engagement of each of the shoes will be produced irrespective of any misalignment.

It will be apparent in all embodiments of the invention thus far shown and described, that the connector has limited universal movement with respect to one contact when being moved into engagement with the other contact, sothat misalignment of the contacts, within predetermined limits, will not be effective to produce an equalized contact pressure, or to reduce or increase the contact area unnecessarily. Further, by the provision of the contact shoes which are spring pressed into engagement between the contacts, it will be apparent that uniform contact pressure of each shoe against its adjacent contact surface will be maintained, regardless of misalignment of the contact, this being due to the fact that the cooperating surfacesI are all formed with the same radius, so that a substantial linev contact of uniform contact area will be maintained at all times, and because of the fioating arrangement of the contact shoes or connector, equalized contact pressure at all points will be maintained. This` is distinctly desirable in circuit controlling means of this type, and the electrical switch connector shown provides for insuring that equalized contact pressure of uniform area will be maintained at all times. l

I am aware 'that various changes may be made in the operating mechanisms of the various embodiments of my invention, and in details of constructionof various of the constituent parts thereof. I therefore do not intend to limit myself to the 'details shown and described, but only in so far asdeiined by the scope and spirit of the appended claims.

I claim:

1.In combination, a pair of spaced apart contact members each having a convex spherical contact surface, a passage-Way through one of said members, a connector having actuating means within said passage-way for moving said connector into and out of engaging contact position, a plurality of individual contact shoes assembled ino and making up said connector, said shoes bridging and completing the electric circuit between said spaced contact members when in engaging contact position, and resilient means individual to each individual contact shoe for maintaining edualized and unvarying pressure and contact between contact shoesaund said spaced contact members for predetermined positions -of misalignment of said spaced contact members.

.2. An electrical connector comprising a connecting member comprising a plurality of individual contact shoes, a pair of spaced apart contact members each having a convex spherical contact surface, resilient means individual to each contact shoefor urging said shoes of said connecting member into equalized pressure contact with said spaced contact members when in engaged position of said connector with said spaced contact members, and actuating means built internally'into one of said spaced contact members for moving said connecting member telescopically over one spaced contact member from open to close position of the connector, while permitting limited universal movement of said connecting member lto accommodate for limited mislaignment of said spaced contact members.

3. An electric switch comprising, in combination, a pair of spaced apart contact members normally adapted to be in axial alignment but likely to be positioned slightly out of alignment and having convex spherical contact portions; a connector member including a plurality of individual contact shoes arranged to surround both said contact members, each of said contact shoes having contact portions for engaging said convex spherical contact portions, support means cooperating with` said contact shoes, and resilient means acting between said support means and said contact shoes for urging sai-d contact shoes intoengagement with said convex spherical contact portions of said contact members; said connector member being movable relative to both said contact members for opening and closing a circuit therethrough.

4i. An electric switch comprising, in combination, a pair of spaced apart contact members normally adapted to be in axial alignment but likely to be positioned slightly out of alignment and having convex spherical contact portions; a connector member including a plurality of individual contact shoes arranged to surround both said contact members, each of said Contact shoes having contact portions for engaging said convex spherical contact portions, support means at each end of said contact shoes, and resilient means individual to each support means and. acting between the same and said contact shoes for urging the contact portions thereof into contact engagement with said spherical contact portions of said contact members; said connector member being movable relative to both said contact members to open and close a circuit therethrough.

' 5. In combination, a pair of spaced apart con# tact mmebers each having a convex spherical contact surface, a passage-way through one of said members, a connector having actuating means within said passageway for moving said connector into and out of engaging contact position, a plurality of individual contact shoes with concave cylindrical contact surfaces assembled into and making up said connector, said shoes bridging and completing the electric circuit between said spaced contact members when in en-l gaging contact position, and resilient means inf dividual to each individual contact shoe for maintaining equalized and unvarying pressure and contact 'between contact shoes and said spaced Contact members for predetermined positions of misalignment of said spaced contact members.

6. An electric switch comprising, in combination, a pair of spaced apart normally relatively stationary contact members normally adapted to be in axial alignment but likely'to be positioned slightly out of alignment and having convex spherical contact portions; and a connector member movable along the common axis of said contact members and including a plurality of individual Contact shoes arranged to surround both said contact members, each contact shoe having a contact surface adjacent each end for engaging the respective spherical contact portions of said contact men'lbers, support means for and movable with Contact shoes, and resilient means individual to each Contact shoe acting between said support means and said Contact shoes for urging said contact shoes into engagement with said convex spherical contact portions of said contact members.

7. An electric switch comprising, in. combination, a of spaced apart normally relatively stationary Contact members normally adapted to be in axial alignment but likely to be positioned slightly ont of alignment and having convex spherical Contact portions; and a connector member movable along the common axis of said contact members an including a plurality of indicontact shoes arranged to surround both end for engaging the respective spherical contact portions of said contact members, support means for and movable with said contact slices, and resilient means acting between said support means and said contact shoes for urging said Contact shoes into engagement with said convex spherical contact portions of said contact members.

8. An electric switch comprising, in combination, a pair of spaced apart normally relatively stationary contact members normally adapted to be in axial alignment but likely to be positioned slightly out of alignment and having convex spherical contact portions; and a connector member movable along the common axis of said contact members and including a plurality of indvidual contact shoes arranged to surround both said Contact members, each Contact shoe having a concave cylindrical Contact surface adjacent each end for engaging the respective spherical contact portions of said contact members, support means for and movable with said contact shoes, and resilient means individual to each contact shoe and acting between said support means and said contact slices for urging said contact shoes into engagement with said convex spherical Contact portions of said contact members.

CHARLES H. KOEHLER. 

